This invention relates to a power conservation system.
In many buildings, such as hotels, motels, apartment buildings and similar buidlings, there is only a single utility meter, and the owner of the building incurs the cost of operating power consuming equipment such as air conditioners serving various units or rooms within the building. Many apartment dwellers or motel guests like to leave the air conditioning on while they are out of the building so that it will be cool immediately when they return. This is of course particularly the case when they personally do not directly pay for utility service.
In view of the foregoing, and for related reasons, it will be appreciated that there is a need for a system to reduce the waste of power resulting from the operation of air conditioners and the like in unoccupied rooms. This need has been a longstanding one, and has led others to propose various types of power conservation systems.
One prior art approach, which has been employed in motels, involves the distribution to motel guests of a special key. When the motel guest checks into the motel, he is given a key which he can use not only to get into the room but also operate a lock that controls the room air conditioner. When the guest checks out, he returns the key, and thus the air conditioner cannot be operated in the room during the periods between rentals. This type of system clearly has drawbacks with respect to use in the environment of an apartment building where generally there are several occupants in each apartment, each of whom has his own key.
The patent literature in this art also shows that others have proposed approaches to this problem. In this connection, reference is made to the following representative prior art patents: U.S. Pat. Nos. 2,756,300--Thiberville; 3,729,735--Dageford; 1,724,930--Hart.
Hart teaches an arrangement whereby the lights of a room in a motel are, in the event that they have been left on, automatically thrown off when the guest closes the door and locks it from the outside. With this approach, the lights remain on and power is wasted whenever the guest forgets to or elects not to lock the door from the outside.
Dageford teaches a remote sending device to control an air conditioning system upon the opening or closing of a window. His device involves an ultrasonic transmitter employing a tuning fork and accordingly entails considerable expense and complexity.
Thiberville teaches a lock controlled switch, and incidentally mentions the possibility of controlling the operation of an air conditioner with his switch. From his description of this matter at column 3, line 55 through column 4, line 9, it appears that his system involves the same kind of approach taken by Hart in that locking from the outside is required to turn off the power consuming equipment.